1. Field of the Invention
The present invention relates to a communication device and a communication system, and particularly relates to a communication device and a communication system which perform radio communication.
2. Description of the Related Art
When communication devices with a plurality of IDs are present on the occasion of performing ID (identifier) authentication using radio, there is the problem that collision of signals occurs and ID authentication is not accurately performed. Since the frequency bands for use in UWB (ultra wide band) communication that is a very high speed radio technology exceeding an optical fiber, the fourth generation cellular phones which are expected to be in actual use in 2010 and the like partially overlap one another, and the fear of interference is not avoided.
Japanese Patent Application Laid-open No. 6-276180 discloses a wireless transmitter-receiver that includes a controller which instructs an operation to tools remotely installed, a transmitting and receiving device which converts mutual information of the above described tools and the above described controller into wireless signals and communicates them, an ID cord storing device which stores ID cords provided for identification of the tools, and a timer generator which generates a timer in accordance with the above described ID cords, and provides time lags by the above described timer generator when the wireless signals collide with each other to retransmit the wireless signals.
When the communication devices with a plurality of IDs are present on the occasion of performing ID authentication using radio as described above, there is the problem that collision of signals occurs and ID authentication is not accurately performed.